Most previous qualitative spatial or spatio-temporal reasoning researches focused only on one single aspect and therefore were inadequate for realistic applications. A representation and reasoning technology integrating topology, size and time information are proposed and applied to a spatio-temporal geographical information system. The representations of topology, size and time are defined and their interdependence is studied. Then an algorithm TriRSAT which can solve the CSP of these three aspects of information is put forward. The representations are used in the constraint base and the TriRSAT is applied to the consistence check of the spatial-temporal data and query. The methods and theories integrating spatio-temporal information effectively can be potentially applied to spatio-temporal database and robot navigation.